大鼠肝癌发生发展过程中肝组织增殖细胞核抗原动态演变规律

目的研究原发性肝细胞癌发生、发展过程中肝组织增殖细胞核抗原(proliferatingcellnuclearanti-gen,PCNA)的动态演变规律。方法将60只SD大鼠按随机数字表法随机分为对照组(20只)和实验组(40只)。用化学致癌剂3,3′-二氨基联苯胺(3,3′-diaminobenzidine,DAB)诱发SD大鼠肝癌,采用免疫组织化学方法连续监测各时相肝组织中PCNA的表达,光镜下观察肝组织的病理变化。结果本实验的诱癌过程可分为炎性变期、增生纤维化期和癌变期3个阶段;PCNA的表达最早出现于炎性变早期汇管区的卵圆细胞中,并在汇管区呈区域性过表达分布;炎性变中期,PCNA表达阳性率达高峰,随后下降,在癌变期又升高,在整个病理演变过程中其表达具波动性。结论在致癌因素的存在下,PCNA首先表达于卵圆细胞;PCNA表达的动态演变对肝癌的发生有一定的预警作用。     

无症状性炎性前列腺炎对血清PSA、fPSA的影响

目的　探讨无症状性炎性前列腺炎(NIH分类Ⅳ型)对血清PSA、fPSA的影响。方法　对比分析36例NIH分类Ⅳ型、42 例有症状性慢性前列腺炎(NIH分类ⅢA型)患者以及22例健康对照组的血清PSA、fPSA、fPSA/tPSA之间的差异。结果　血 清PSA、fPSA、fPSA/tPSA在Ⅳ型和ⅢA型前列腺炎患者间差异无显著性(P>0.05),但与正常对照组比较差异有显著性(P< 0.01)。结论　NIH分类Ⅳ型前列腺炎可引起血清PSA、fPSA升高。对无症状、高血清PSA患者行前列腺活检前,应考虑到患 Ⅳ型前列腺炎的可能。     

大鼠抗GBM肾炎模型的建立及不同病期的生化指标和肾组织病理学观察

目的：为研究人类新月体抗肾炎的发病机制，建立大鼠抗肾小球基底膜（BGM）肾炎的动物模型，方法：提取S－D大鼠GBM抗原，将此抗原免疫新西兰白兔获得抗血清，再将此抗血清从尾静脉一次性注射给S－D大鼠。实验分2组：肾炎模型组及正常对照组。定期于第4天、第14天第第21天检测大鼠24h尿蛋白，血肌酐及血尿素的含量和肾组织病理学改变。结果：大鼠肾炎模型组：大鼠注射抗血清后于第4天出现大量蛋白尿，第14天血肌酐，血尿素显著升高，并持续上升，肾组织病理表现为肾小球内细胞数明显增加，大量新月体形成及蛋白管型，GBM呈不规则增厚，足突融合，内皮细胞脱落，坏死，免疫荧光检查见IgG、鼠IgG沿GBM线形分布，大鼠正常对照组以上指标均无明显改变。结论：通过动态观察大鼠抗GBM肾炎的病变变化，证实该模型病变与人类新月体性肾炎的病变较为一致，该模型可用于探讨人类新月体体肾炎的实验研究。     

Diagnostic value of serum prostate-specific antigen in hemodialysis patients

BACKGROUND: The value of serum prostate-specific antigen (PSA) screening was examined to detect prostate cancer in men receiving hemodialysis. METHODS: Forty-one male patients age 60-95 (median age, 70 years) receiving hemodialysis were investigated for PSA levels. We set the cut-off point at 4 ng/mL (the usual reference range). Digital rectal examination (DRE) and transrectal ultrasonography (TRUS) of the prostate were performed in patients whose PSA was more than 4 ng/mL and/or who expected further examination of the prostate. When prostate cancer was suspected, biopsy of the prostate was performed. In patients with prostate cancer, magnetic resonance imaging, computed tomography and bone scintigraphy were performed to diagnose the clinical stage. RESULTS: The mean serum level of PSA was 2.10 +/- 0.49 ng/mL. In this screening study, four of 41 men required further examinations for prostate cancer. Two of four refused further examinations. The other two were diagnosed with prostate cancer. The incidence of prostate cancer was at least 5% in our hemodialysis patients. One man, whose clinical stage was T2aN0M0, was treated with radical retropubic prostatectomy. Another man, whose clinical stage was T2bN0M0, was treated with luteinizing hormone-releasing hormone analogue. CONCLUSION: In our preliminary study, prostate cancer screening with PSA was useful for the early detection of prostate cancer in hemodialysis patients. If possible, DRE and TRUS should be performed in conjunction with PSA tests.     

CD24 expression on human keratinocytes

Abstract: CD24 or Nectadrin is a cell surface glycoprotein expressed in pre-B lymphocytes, T lymphocytes, neurons, muscle cells and carcinoma cells. Its function is not completely known, but it has been suggested that it is involved in cell adhesion and signalling. CD24 has recently been identified as the human molecule homologous to the murine heat-stable antigen (HSA). HSA is expressed by murine keratinocytes and delivers costimulatory signals in T-cell activation. Long-term cultures of normal human keratinocytes (HKC) were obtained from skin of human female breast sections and either left untreated or were treated with phorbol-12-myristate-13-acetate (PMA) at 10–100 ng/ml, calcium 0.5–2 mM or IFN-γ 100–1000 U/ml, for 24–48 h. Using RT-PCR and flow cytometry we showed that HKC express low levels of CD24 even under basal conditions, and the treatment with calcium, PMA or IFN-γ increased levels of CD24 mRNA and protein. To the best of our knowledge, this is the first report to measure CD24 expression and production by cultured HKC in basal conditions and after stimulation. Further studies are needed to determine biological and therapeutical relevance of these findings.     

Seminal Fluid and the Expression of MHC Class I Antigens in the Placenta of the Rat

PROBLEM : To determine whether seminal fluid influences the expression of MHC class I antigens on the surface of basal trophoblast cells in the placenta of the rat. METHODS : Transfer of DA × DA embryos into a WF (allogeneic) or DA (syngeneic) recipient made pseudopregnant by hormonal treatment followed by mating with a vasectomized male (seminal fluid) or by mechanical stimulation (no seminal fluid). Antigen expression was determined by electron microscopic immunocytochemistry using the appropriate gold-labeled monoclonal antibodies. RESULTS : Seminal fluid did not affect the expression of MHC class I antigens on the surface of the basal trophoblast in either allogeneic or syngeneic matings. CONCLUSIONS : The suppression of the expression of paternal class I antigens on the surface of the basal trophoblast cells in allogeneic pregnancies most likely occurs at the genome level shortly after fertilization.     

Human T cell responses to recombinant mite antigens of Dermatophagoides farinae

We studied T cell responses to four glutathione S transferase (GST)-fused mite antigens prepared in our laboratory using peripheral blood lymphocytes from mite-sensitive patients with bronchial asthma. Of the four recombinant antigens, purified GST-Mag3 had the strongest ability to cause patients' lymphocytes to proliferate, and its potency was almost comparable to that of crude mite bodies (Dfb) and faeces (Dff) antigens and a purified major antigen, Der f 2. The responder lymphocytes were mainly T cells, because the proliferative response was depleted by the treatment of lymphocytes with anti-CD3 antibody and complement, but not with anti-CD20 antibody and complement. The responsiveness of lymphocytes to GST-Mag3 correlated with that to Der f 2, but GST-Mag3 displayed slightly higher activity to stimulate lymphocytes than Der f 2. Simultaneously, the levels of Dff- and GST-Mag3-specific IgE antibodies correlated with the responsiveness of lymphocytes to GST-Mag3. These results suggest that Mag3 is a new valuable antigen for the response of T cell proliferation in mite-sensitive patients.     

Epitope Context and Reshaping of Activated T Helper Cell Repertoire

In recent years, a growing interest in the study of peptide antigenicity in relation to the role of flanking sequences and protein topology in processing, presentation, and recognition has been observed. However, the information available on the antigenicity of recombinant fusion proteins and their effect on the selection of antigen receptor repertoires is limited. To analyze the role of molecular topology of T epitopes in a system relevant to human pathology, we have used the bacterially expressed Schistosoma japonicum glutathione S transferase (GST) to construct recombinant antigens containing HIV-1 derived T cell determinants, and human T cell clones specific for these determinants. We found that antigenicity of a given GST—peptide combination was not the same when T cells and antigen presenting cells from different individuals were tested. Our results show that differences in processing and presentation of chimeric proteins are not dictated by the use of diverse restriction elements. We also found that the context in which an antigenic peptide is delivered affects the recruited repertoire as defined according to T cell receptor Vβ usage and fine specificities of selected T cells.